package com.yc.pos;

import java.util.LinkedList;

public class Session
{
    private LinkedList link;

    public Session()
    {
        this.link = new LinkedList();
    }
    public void add(Object obj) {
        this.link.addFirst(obj);
    }
    public Object get() {
        return this.link.removeLast();
    }
    public boolean isNull() {
        return this.link.isEmpty();
    }
}